Hard rock percussion drill bit with paraboloid PCD inserts



FIG. 1 is a greatly enlarged side elevational view of a hard rock percussion drill bit embodying the invention.

FIG. 2 is a top plan view thereof.

FIG. 3 is a bottom view thereof.

FIG. 4 is a side elevation thereof, as rotated 90° from the FIG. 1 position, and partially fragmented and broken away to illustrate the interiorly threaded bore at the bottom end; and,

FIG. 5 is a perspective view of thereof. 

The ornamental design for a hard rock percussion drill bit with paraboloid PCD inserts, as shown and described. 